Kathleen Vohs is obsessed with money. Not acquiring it, but studying what the pursuit of it does to us.

Her groundbreaking research is motivated partly by her own experience with money, a not-exactly-rags to relative riches story.

After toiling as a post-doctorate fellow on meager salaries for three years, Vohs landed a faculty position in 2003 that brought a significant bump in income.

Subtly but suddenly, her lifestyle changed. She stopped asking friends to give her rides to the airport and took taxis. Then she hired a personal shopper. "It was really weird. [Having money] ends up changing the way you live your life in ways that are not totally expected," said Vohs, now an associate professor at the University of Minnesota's Carlson School of Management. "You don't make a ton of money, you're not on yachts or things, but you start making different choices. I became more independent and less interdependent."

Vohs discovered that little research had been done on "what happens to people's minds in the context of wealth." Dozens of experiments with thousands of subjects later, Vohs, 38, is an internationally renowned, oft-published expert on the powerful psychological effects of money.

Some tests have involved money directly -- handling clean, crisp dollar bills vs. soiled cash at a farmer's market, or being in a room with stacks of Monopoly money -- but most are "super subtle," she said. What's consistent are the findings: Subjects with money on their minds are self-sufficient, self-focused and anything but selfless.

"In all of our experiments, people who are reminded of money are really good at pursuing goals," said Vohs, "but they're not that interpersonally kind or warm. They're kind of standoffish, keeping in their own head, not interested in being friends with anyone."

Vohs gestures with her hands while talking almost breathlessly, her mind clearly whirring along even faster than her hands or vocal cords. "So what you get are high-motivated people who are not very socially sensitive," she continued. As in antisocial? "Nope. Antisocial suggests things like they're actively pushing people away. It's more like they're siloed."

Vohs is quick to point out that she's not speaking of the wealthy here, but rather those chasing after wealth.

"We find that certain really wealthy people don't think about money all that often," she said, "and sometimes middle-class people think about money a lot and poor people think about money a lot. So it's more like how much money is on your mind rather than whether you yourself have a lot of it."

'A good listener'

Growing up middle class in North St. Paul, the daughter of an accountant and a nurse, Vohs never saw the dollar as almighty. "I think I wanted to be well off in a general sense," she said "but crazy rich? No, no, no."

What stoked her ardor was school. When they first met at John Glenn Middle School, classmate Kim Wirka said, Vohs "always pushed herself to go further than other people." But Vohs was no staid bookworm. "She was funny and fun to be around, a good listener, someone to share growing up with."

After graduating from North St. Paul High, Vohs headed to Gustavus Adolphus College, and in short order she had decided on a major. "Early on in my first year of college, I read a psychology textbook," Vohs said, "and I came back to the dorm and told my friends, 'Did you know that if you put women in front of a pink wall, they can do more?' I just ate it up. It was like finding a love."

After graduating summa cum laude, Vohs stayed on the scholarly track. "Being accepted into Dartmouth, I think that was a pivotal point for Katy," Wirka said of her friend and recent 20-year high-school reunion companion. "Up to then, she was just a Minnesota girl."

Vohs went on to international acclaim, earning a Ph.D. in psychology and brain science in 2000 and a post-doctorate fellowships for three years before landing a faculty job at the University of British Columbia. Her non-teaching work was focused heavily on self-control and self-esteem, but once her "personal shopper" revelation kicked in, Vohs foresaw a treasure trove of potential research to be done on money.

By that point, Vohs already had a reputation as a dogged and enterprising researcher.

"She has lots of energy and is very creative," said Florida State professor of social psychology Roy Baumeister, who has collaborated with Vohs on dozens of works. "Her strength and resourcefulness are indomitable. There are always setbacks, and she will say, 'We can fix this, let's do another study, something that will satisfy the reviewers. We can find more, come up with new ways of addressing this.'

"She could be called a closer, like in baseball. You have a paper that has proceeded pretty well, and she would always come through with what we needed to finish."

Cuts across all demographics

Since signing on in 2008 at the U of M, where she teaches MBAs about neural science and the psychology of the consumer ("which is super cool"), Vohs has spearheaded a wide range of research to get the lowdown on dough.

In one experiment, subjects in a lab filled out questionnaires while, in the background, a computer screen showed either fish swimming or money floating underwater ("because for some reason somebody made a screen saver like that," Vohs said with a chuckle). The participants then were taken into another room and told to move a chair from the corner and sit down. Those who had had the money backdrop "put more physical distance between themselves and others," Vohs said.

The sundry tests reinforced the theory that being money-centric makes people very goal-oriented but less social -- and can even blunt physical and social pain -- and the pattern held true across all demographics: age, gender, ethnicity, even socio-economic background.

"We looked into things like how wealthy were you growing up, and how wealthy you expect to be, and all of these people reacted to the concept of money the same way," Vohs said. "And that is fascinating to me."

While allowing that her findings are "absolutely true," another researcher is investigating how money can have less self-focused effects.

"When we get money, the first thing we think about is ourselves," said Michael Norton, an associate professor at Harvard Business School, "not because we're bad people, but because [money] has that effect."

So if the intense desire for money is usually a bad thing, what are rich people like?

"That's the million-dollar question. I don't have a good answer on that question,'' Vohs said.